I see that you started from NAND flash driver for eCos to wire it with
UFFS core then. Fortunately or unfortunately I have no NAND flash parts
to play with it, and I looked in a side of a UFFS SIMRAM class which was
implemented by UFFS's author to debug and play with UFFS (I did import
uffs-1.3.0 sources). So, that my stub sandbox FS_UFFS does not seat on
FLASH_IO layer, instead, I thought to try to implement of a set of the
file system commands like uffs_mount, uffs_umount, uffs_open, etc. to
get the UFFS stuff like the eCos RAMFS file system for the test
purposed.